User interface for a portion of a display screen



FIG. 1 is a front view of a user interface for a portion of a display screen showing my new design; and,

FIG. 2 is an enlarged front view thereof, the user interface is shown separately for clarity of illustration.

In both figure views, the broken line showing of the text forms no part of the claimed design. The broken line showing of a portion of a display screen in FIG. 1 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a user interface for a portion of a display screen, as shown and described. 